Catalytic composition of organotin compounds

ABSTRACT

The present invention relates to catalytic compositions for esterification, transestrification and polycondensation reactions, a process for the catalysis of said reactions employing such catalytic compositions and polyesters for resins obtainable by this process.

The present invention relates to catalytic compositions foresterification, transesterification and polycondensation reactions, aprocess for the catalysis of said reactions employing such catalyticcompositions and polyesters or resins obtainable by this process.

Catalytic systems containing organotin compounds are widely known.

E.g. compounds of the formula [(RSn)₁₂O₁₄(OH)₆]²⁺ are described mainlyin connection with their interesting structure in: H. Puff, H. Reuter,J. Organomet. Chem. 1989, 373, 173-184; D. Dakternieks, H. Zhu, E. R. T.Tiekink, R. Colton, J. Organomet. Chem. 1994, 476, 33-40; S. Durand, K.Sakamoto, T. Fukuyama, A. Orita, J. Otera, A. Duthie, D. Dakternieks, M.Schulte, K. Jurkschat, Organometallics 2000, 19, 3220-3223.

Compounds of said type C(RSn)₁₂O₁₄(OH)₆]²⁺ are further described to showa poor performance in catalyzing or activating reagents and compoundswithin the acetylation reaction of acetic anhydride with an alcohol (S.Durand, K. Sakamoto, T. Fukuyama, A. Orita, J. Otera, A. Duthie, D.Dakternieks, M. Schulte, K. Jurkschat, Organometallics 2000, 19,3220-3223.)

It is known for compounds of the formula [(BuSn)₁₂O₁₄(OH)₆]²⁺ whenstored in methanol, that a replacement of two structural importantμ2-bridged OH groups of the cluster against OCH₃ units can occur (D.Dakternieks, H. Zhu, E. R. T. Tiekink, R. Colton, J. Organomet. Chem.1994, 476, 33-40).

Furthermore is known that during the production of polyesters for someapplications for example wrappings and technical yarns, acrystallization and polycondensation in the solid state is carried out(U.S. Pat. No. 4,064,112, U.S. Pat. No. 4,263,425, U.S. Pat. No.5,362,844). In other applications, fibers or filaments are spun directlyand direct preforms are produced in a process wherein an intermediatetransfer into the solid state and a repeated remelting is not applied.

Conventional polyester compositions are connected with a series ofdisadvantages (general summary in: Handbook of polyester thermoplastics,1st edition, Wiley-VCH, Weinheim, 2002). Among these disadvantages arein particular:

-   -   Necessity of high temperatures for the synthesis    -   High catalyst concentration (100-500 ppm [as metal])    -   Degradation processes under processing and polycondensation        conditions; for example formation of vinyl esters and due to the        formation of acetic aldehyde in polyethylene terephthalate        (PET), formation of acrolein in polypropylene terephthalate        (PPT) and tetrahydrofuran formation in polybutylene        terephthalate (PBT).    -   Limited use of the catalyst systems, dependent on the technology        of the process and the chemical structure of the substrate;        classic titanium based catalysts cannot be added for example        during the esterification- and/or pre/condensation step, as        these are readily hydrolyzed to inactivate titanium oxides.    -   Application of the catalyst system only in selected process        stages for example only during the esterifications- or only        during the transesterification- or only during the        polycondensation stage.    -   Optical turbidity of the produced polyester for example by        deposits of elementary metal impurities as this can occur by the        use of antimony based catalyst systems.    -   Discoloration of the polyester by the catalyst itself, for        example titanium based catalyst systems cause a yellow coloring        of the polymer or formation of chromophor by-products,        respectively.    -   Problematic metering and addition of catalysts and catalyst        formulations.

Object of the present invention is to provide a catalytic composition,suitable for catalyzing esterification, transesterification andpolycondensation reactions, an improved process of catalyzedesterification, transesterification and polycondensation reactions andthe production of improved polyesters for bottles, films, foils, yarn,molded padding, resins for powder coatings and technical syntheticmaterials, which avoid the disadvantages of the prior art.

The problem is solved according to the invention by a catalyticcomposition according to claim 1, a process for the preparation of suchcatalytic compositions according to claim 7, their use according toclaim 10 and polyesters or resins according to claims 18 and 19.

A first embodiment of the present invention refers to a catalyticcomposition for esterification, transesterification and polycondensationreactions of dicarboxylic acids, polycarboxylic acids, hydroxycarboxylic acids and/or their derivatives and alcohols containing atleast one tin compound of the general formula (I):[(R¹Sn)_(l)(OH)_(m-n)(OR²)_(n)O_(o)]^(p+)A^(q−) _(p/q)  (formula I)wherein:

-   R¹ and R² each independently is a linear, branched or cyclic alkyl    group or aryl group having 1 to 12 carbon atoms,-   A^(q−) is an anion,-   l is at least 1,-   m=0 to 20,-   n=0 to 20,-   p=0 to 6,-   o=0 to 20 and-   q=0 to 6.

Preferred examples for R¹ are methyl, ethyl, n-propyl, iso-propyl,n-butyl, 2-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl, neopentyl radical, tert-pentyl, hexyl, heptyl, n-octyl, iso-octyl,2-ethyl-1-hexyl, 2,2,4-trimethylpentyl, nonyl, decyl, dodecyl,n-dodecyl, cyclopentyl, cyclohexyl, cycloheptyl, methylcyclohexyl,vinyl, 1-propenyl, 2-propenyl, naphthyl, anthranyl, phenanthryl,o-tolyl, p-tolyl, m-tolyl, xylyl, ethyl phenyl, mesityl, phenyl, benzyl.Favored substituents for the invention are: Methyl, n-butyl, n-octyl andn-dodecyl.

Examples for R² are methyl, ethyl, n-propyl, iso-propyl, n-butyl,2-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl, neo pentyl,tert-pentyl, hexyl, heptyl, n-octyl, iso-octyl, 2,2,4-trimethylpentyl,2-hydroxy-1-ethylpentyl, hydroxy-neo-pentyl, 2-ethyl-1-hexyl, nonyl,decyl, dodecyl, n-dodecyl, cyclopentyl, cyclohexyl, cycloheptyl,methylcyclohexyl, vinyl, 1-propenyl, 2-propenyl, naphthyl, anthryl,phenanthryl, o-tolyl, p-tolyl, m-tolyl, xylyl, ethyl phenyl, mesityl,phenyl, benzyl. Favored substituents for the invention are: Methyl,ethyl, n-propyl, iso-propyl, n-butyl, 2-butyl, iso-butyl, tert-butyl.

Preferred examples for A are: O, OH, methanolate, ethanolate,n-propanolate, iso-propanolate, n-butanolate, 2-butanolate,iso-butanolate, tert-butanolate, n-pentanolate, iso-pentanolate,neo-pentanolate, tert-pentanolate, 2-methyl-1-butanolate, hexanolate,heptanolate, n-octanolate, iso-octanolate, 2,2,4-trimethylpentanolate,nonanolate, decanolate, dodecanolate, n-dodecanolate, cyclopentanolate,cyclohexanolate, cycloheptanolate, methylcyclohexanolate, glycolate,glycerate, pinakolate neopentylglycolate, vinylalkoholate,propargylalkoholate, 2-ethyl-1-hexanolate, formiate, acetate,propionate, butyrate, valeriate, caprate, caprylate, caprinate, laurate,laureate, 2-ethyl-1-hexanoate, neodecanoate, palmitate, stearate,benzoate, terephthalate, phthalate, isoterephthalate, acrylate,methacrylate, crotonate, isocrotonate, vinylacetate, oleate, sorbate,linolate, linolenate, trifluoracetate, methansulphonate,ethanesulphonate, n-propanesulphonate, iso-propanesulphonate,n-butanesulphonate, 2-butanesulphonate, iso-butanesulphonate,tert-butanesulphonate, n-pentanesulphonate, iso-pentanesulphonate,neo-pentanesulphonate, tert-pentanesulphonate,2-methyl-1-butanesulphonate, hexanesulphonate, heptanesulphonate,n-octanesulphonate, iso-octanesulphonate, 2,2,4-trimethylpentansulphonate, nonansulphonate, decansulphonate, dodecanesulphonate,n-dodecanesulphonate, cyclopentanesulphonate, cyclohexane sulphonate,cycloheptanesulphonate, methylcyclohexanesulphonate p-toluolsulphonate,oxalate, malonate, succinate, glutarate, adipate, fumarate, maleinate,carboxylates of the following monoesters: methylmaleic acid monoester,ethylmaleic acid monoester, butylmaleic monoester, n-butylmaleic acidmonoester, 2-butylmaleic acid monoester, iso-butylmaleic acid monoester,tert-butylmaleic acid monoester, n-pentylmaleic acid monoester,isopentylmaleic acid monoester, neo-pentylmaleic acid monoester,tert-pentylmaleic acid monoester, 2-methyl-1-butylmaleic acid monoester,hexylmaleic acid monoester, heptylmaleic acid monoester, n-octylmaleicacid monoester, iso-octylmaleic acid monoester,2,2,4-trimethylpentylmaleic acid monoester, nonylmaleic acid monoester,decylmaleic acid monoester, dodecylmaleic acid monoester,n-dodecylmaleic acid monoester, cyclopentylmaleic acid monoester,cyclohexylmaleic acid monoester, cycloheptylmaleic acid monoester,methylcyclohexylmaleic acid monoester, glycolmaleic acid monoester,glycerolmaleic acid monoester, pinakolmaleic acid monoester,neopentylglycolmaleic acid monoester, vinylmaleic acid monoester,propargylmaleic acid monoester and 2-ethyl-1-hexylmaleic acid monoester,citrate, lactate, tartrate, naphthenate, naphthalene-2,6-dlcarboxalate,naphthalene-1,6-dicarboxalate, F, Cl, ClO, ClO₂, ClO₃, ClO₄, CO₃, Br, J,CN, SCN, OCN, sulphate, hydrogensulphate, sulphite, hydrogensulphite,sulphide, phosphate, hydrogenphosphate, dlhydrogenphosphate,bis(2-ethyl-1-hexyl)phosphate, butylphosphate, dibutylphosphate,3-phosphonopropionate, phenylphosphoic acid, benzylphosphoic acid,p-aminophosphoic acid, n-octylphosphoic acid. Favored substituents forthe invention are: methanolate, ethanolate, n-propanolate,iso-propanolate, n-butanolate, 2-butanolate, iso-butanolate,tert-butanolate, bis(2-ethyl-1-hexyl)phosphate, neodecanoat,2-ethylhexanoat, and 2-ethyl-1-hexylmaleic acid monoester,trifluoracetate, p-toluolsulphonate, Cl, Br, J, sulphate, hydrogensulphate, phosphate, hydrogen phosphate and dihydrogen phosphate.

Said catalytic compositions proved highly effective in the catalysis ofesterification, transesterification, polycondensation,polyesterification and polytransesterification reactions. Thesederivatives of dicarboxylic acids, polycarboxylic acids and/or hydroxycarboxylic acids according to the invention include e.g. esters andhalogenides, but not anhydrides.

In a preferred embodiment of the invention, said catalytic compositionis characterized in that the anion A^(q−) is O²⁻, —OH⁻, a linear,branched or cyclic alkyl carboxy or aryl carboxy group or linear,branched or cyclic alkoxy group each having 1 to 12 carbon atoms, theanion of a mineral acid or a metalate.

In particular, said anion A^(q−) is a sulphate, sulphite, phosphate,halogenide or pseudo-halogenide, titanate, zirconate, aluminate orzincate anion.

According to a particularly preferred embodiment of the invention, saidcatalytic composition is characterized in that n=1 to 20.

In this case a specific structure within the[(R¹Sn)_(l)(OH)_(m-n)(OR²)_(n)O_(o)]^(p)+A^(q−) _(p/q)-unit is createdby introduction of 1 to 20 alkoxy groups (OR²).

Most preferred catalytic compositions according to the invention arecharacterized in that I=12, m=6, n=0 to 6, o=14 and p=2.

Since the chemical composition containing a tin compound according toformula I, having R¹=butyl, R²=methyl, I=12, m=6, n=2, o=14, p=2, A=Cl,q=1, as such is known but is described to be used for different purposesthan that of the present invention, the catalytic composition accordingto the present invention does not encompass the protection of saidspecies as such.

According to the invention the specific structure within[(R¹Sn)_(l)(OH)_(m-n)(OR²)_(n)O_(o)]^(p+)A^(q−) _(p/q)-unit is achievedby introduction of 1 to 20, preferably 1 to 6 alkoxy groups (OR²) intothe unit [(R¹Sn)_(l)(OH)_(m)O_(o)]^(p+)A^(q−) _(p/q)- by conversion withsuitable metal alkoxides (metal alcoholates).

Preferred examples for said metal alkoxides are: Li, Na, K, Rb, Mg, Ca,Sr, Ba, Sc, Ti, Zr, Hf, Zn or Al-methanolate-ethanolate, -n-propanolate,-iso-propanolate, -n-butanolate, -2-butanolate, -iso-butanolate,-tert-butanolate, -neo-pentanolate, -isopentanolate, -neo-pentanolate,-tert-pentanolate, -2-methyl-1-butanolate, -hexanolate, -heptanolate,-n-octanolate, -iso-octanolate, -2,2,4-trimethylpentanolate,-nonanolate, -decanolate, -dodecanolate, -n-dodecanolate,-cyclopentanolate, -cyclohexanolate, -cycloheptanolate,-methylcyclohexanolate, -glycolate, -glycerate, -pinakolate,-neopentylglycolate, -vinylalcoholate, -propargylalcoholate,-2-ethyl-1-hexanolate. Favored metal alcoholates are: Sodiummethanolate, potassium t-butylate, aluminium methanolate-ethanolate,-n-propanolate, -iso-propanolate, -n-butanolate, -2-butanolate,-iso-butanolate, -tert-butanolate, -neo-pentanolate and-iso-pentanolate, titan tetra-butanolate.

According to the invention the conversion of the units[(R¹Sn)_(l)(OH)_(m)O_(o)]^(p+)A^(q−) _(p/q) with a metal alkoxide ispreferably carried out using said metal alkoxide in a proportion of1:0.0001 up to 1:20 by mole, in particular 1:4 to 1:6.

It is furthermore preferred that the side products resulting from saidconversion of the metal alkoxides with[(R¹Sn)_(l)(OH)_(m)O_(o)]^(p+)A^(q−) _(p/q)-units remain in the reactionmixture. These side products include e.g. metallic oxides, metalhydroxides and alkoxy metal hydroxides further to the catalyticallyactive compounds [(R¹Sn)_(l)(OH)_(m-n)(OR²)_(n)O_(o)]^(p+)A^(q−) _(p/q).The side products of the metal alkoxides do not affect the activity ofthe desired compounds [(R¹Sn)_(l)(OH)_(m-n)(OR²)_(n)O_(o)]^(p+)A^(q−)_(p/q).

In a further embodiment of the invention, the catalytic composition asdefined above is used for the continuous or batchwise production ofesters or polycondensation products by esterification,transesterification, polyesterification or polytransesterificationreaction.

Esterification, transesterification, polycondensation,polyesterification and polytransesterification reactions are catalyzedand accelerated by the catalytic compositions according to theinvention. The inventors have shown that in comparison to conventionalmethods lesser amounts of catalyst and lesser amounts of stabilizer leadto comparable results. In addition, even high-viscous polyesters may beproduced in a direct process in by far shorter reaction times. The novelcatalytic composition of the invention is further resistant tohydrolysis and may be added already during the esterification phase andthe precondensation phase or later as an active component.

Preferably, the catalytic composition according to the invention may beused for a polyesterification reaction of a dicarboxylic acid derivativewith a mono, divalent or polyvalent alcohol.

It is particularly preferred to employ derivatives of di, orpolycarboxylic acids being selected from the group of esters orhalogenides.

Dicarboxylic acids (carboxylic acids, containing at least two carboxylgroups), e.g. terephthalic acid, 2,6-naphthalene dicarboxylic acid,isophthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 4,4-bisphenyl dicarboxylic acids, adipic acid,phthalic acid, alkane dicarboxylic acids, halogen derivates of thementioned dicarboxylic acids for example tetrabromophthalic acid, andcopolymers of the mentioned dicarboxylic acids or the esters of thementioned carboxylic acids for example dimethyl terephthalate,bis(hydroxyethyl)terephthalate, 2,6-dimethylnaphthalate,1,6-dimethylnaphthalate and others are preferred according to theinvention.

Polyvalent alcohols, such as ethylene glycol, 1,3-propane diol,1,4-butane diol and/or 1,4-cyclohexane dimethanol, di-, triethyleneglycol, polyglycols with a molecular weight below 1000 or neopentylglycol, are preferably employed.

The catalytic compositions of the invention may further advantageouslybe used for the production of polyesters from hydroxycarboxylic acidssuch as p-hydroxybenzoic acid, salicylic acid, lactic acid, glycol acidand their co-polyesters with the dicarboxylic acids and/or diolsdescribed above.

It is also preferred to employ derivatives of hydroxycarboxylic acidsbeing preferentially selected from esters.

Further recycled polyester material might be used as co/monomer withinthe scope of the invention.

The metal concentration of the catalytically effective metal compound ispreferably 0.1 ppm to 1 mole-%, in particular 10 ppm to 100 ppm, mostpreferred 20 to 50 ppm with reference to the acid or derivative to bereacted.

The catalytic composition used for the production of polyester may beadded during the period before the beginning of the esterificationand/or transesterification until shortly before the end of thepolycondensation, favored during the esterification and/ortransesterification or before the precondensation steps of theproduction process.

A solvent or suspending agent can be added to the tin compound prior orduring the manufacturing of the catalytic composition and/or saidesterification, transesterification, polyesterification orpolytransesterification reaction.

As solvents or suspending agents for the catalyst an alcohol and/or analkane diol can be employed, favored are 1,2-ethane diol, 1,3-propanediol, 1,4-butane diol, 2,2-dimethylpropane-1,3-diol.

The solvent or suspending agent used according to the invention may bedifferent or the same in the manufacturing of said catalytic compositionand said esterification, transesterification, polyesterification orpolytransesterification reaction.

A preferred solvent or suspending agent employed in the invention isbeing selected from the group of mono-, di- or polyvalent alcohols beingreacted in said esterification, transesterification, polyesterificationor polytransesterification reaction.

Further preferred solvent or suspending agents include an organic liquidthat is indifferent with respect to the polyester production process.Examples for such indifferent organic liquids are alkanes, cycloalkanesor benzene derivatives such as benzene, toluene or xylenes. Moreover,water or a mixture of water with an alcohol or a polyvalent may beemployed as solvent and/or suspending agent.

Further additives for a color correction such as cobalt salts or organicdyes or pigments may be added to the reaction mixture, preferably inamounts of 0.0001-5% by weight, in relation to the acid or derivative tobe reacted.

The polyester available by the process using the catalytic compositionsof the invention shows at least comparable qualities with respect toprocessibility as traditional polyesters, e.g. catalyzed with antimony.In comparison to conventional high-viscosity melt polymerisations,resins produced using the catalytic compositions described by theinvention show a relatively low content of acetic aldehyde. Inparticular the polyesters synthesized with the process described by theinvention show a narrow molecular weight distribution, a hightranslucency and give a polymer with a high, desired blue shift. Apolymer of high viscosities, unlike the state of the art using Sbcatalysts, obtained without difficulty.

The polymers, produced using catalytic compositions of the inventionshow a high blue shift (negative b-values; color values determined byusing the CIE-Lab 100 color system with spectral reference beam colormeasuring instrument LUCI 100, Dr. Lange).

The polyesters manufactured by a process using the catalyticcompositions of the invention are made by esterification and,optionally, subsequent polycondensation. These polyesters are especiallysuited for bottles, films, foils, yarn and/or molded padding, or resinsfor powder coatings or technical synthetic materials,

Preferred polyesters according to the invention include:

-   a) polyethylene terephthalate (PET), containing 0.1-10 mass %    diethylene glycol and 0-10 mass % of isophthalic acid,    2-hydroxy-isophthalic acid, p-hydroxyisophthalic acid,    2,6-naphthalenedicarboxylic acid and/or 1,4-cyclohexane dimethanol    as co-monomer;-   b) polyester for powder coatings mainly    poly-2,2-dimethylpropyl-1,3-terephthalate;-   c) polypropylene terephthalate (PPT);-   d) polyester polyols as for example polydiethyleneglycol    terephthalate;-   e) polybutylene terephthalates (PBT);-   f) polynaphthalene terephthalates (PNT)-   g) polyethylene naphthalate (PEN).

The following examples illustrate the invention further without,however, limiting the invention. Unless otherwise indicated, parts andpercentages relate to the weight, as in the remainder of thedescription.

Further subjects of the invention are described by the claims and are intotal part of the description of the present invention.

EXAMPLES Example 1 List of catalytically acting ti-containingcompositions:

Apparatus:

250 ml three necked round bottom flask, tap funnel, magnetic stirrer,water separator, rotary evaporator.

Starting Materials, Quantities monobutylin oxide 20.88 g  [0.10 mol]bis(2-ethylhexyl) phosphate  5.15 g  [0.016 mol] 1a) without alcoholate1b) titanium tetrabutanolate  4.25 g [0.0125 mol] 1c) sodium methanolate 2.70 g  [0.05 mol] 1d) aluminum triethoxide  2.60 g  [0.016 mol] 1e)aluminum tri(sec-butoxide)  4.40 g  [0.016 mol] 1f) aluminumtri(isopropoxide)  3.39 g  [0.016 mol]

Synthesis

Monobutyltin oxide was suspended In xylene (150 ml),bis(2-ethylhexyl)phosphate was added within 10 min and the suspension Isheated under reflux until the water formation stopped. After reachingroom temperature the reaction was filtered. The metal alcoholate wasadded to the filtrate, which was then heated under reflux for anadditional hour. The product was received after removal of the solventunder reduced pressure.

Further Alkyltin Catalysts:

Comparative Example 1g (Tributyltin (2-ethylhexanoate)

A three-necked flask equipped with mechanical mixer, heating,thermometer and vacuum distillation bridge was, under nitrogenprotective atmosphere, filled with 149 9 (0,25 Mol)hexabutyidistannoxane and 72,1 g (0,5 Mol) 2-ethylhexanoic acid. Thereaction mixture was heated up on 80° C. To separate from the reactionwater a vacuum of 1 mbar was applied, and the reaction mixture wasstirred another 1 h at this temperature.

Yield: 209,8 g (theoretical. 212,1 g) a clear, bright liquid. Elementalanalysis: Sn content =27,8%. The production of the examples andcomparative examples 1h to In followed the same procedure.

Comparative example 1h: Dibutyltin bis(2-ethylhexanoate) Example 1l:monobutyltin tris(2-ethylhexanoate) Comparative example 1J: dibutyltinpinacolate Example 1k: monooctylstannoic acid Example 11:monobutylstannoic acid Example 1m: monooctyltin tris(2-ethylhexanoate)Example 1n: monododecyltin tris(2-ethylhexanoate) Example 2 CatalystTest by Synthesis of a Resin for Powder Coatings

Starting Materials, Quantities terephthalic acid  83.07 g [0.50 mol]neopentyl glycol (2,2-dimethyl-1,3-propandiol) 104.15 g [1.00 mol]catalyst: 0.05% [m/m] (as metal)

Synthesis

Catalyst, neopentyl glycol and terephthalic acid were given Into a 250ml three necked round bottom flask. The mixture was heated to a maximumby the means of a heating mantel and the reaction water was distilledoff and the amount was measured.

The reaction time equals the time between the first water formation andthe clear point” of the reaction.

Table 1 shows the acceleration of the reaction time In the describedresin synthesis with the mixtures of examples 1a, 1b, 1c, 1d, 1e, If Incomparison with the uncatalized reaction or with monobutyltin oxide(0,05% [m/m]) as catalyst. TABLE 1 Reaction time of the mixtures a-f incomparison. [min] Catalyst Volume H₂O [ml]: Reac- (0.05% as 15 30 45 6075 90 105 120 135 150 165 180 tion Sn) min min min min min min min minmin min min min time Remarks Without 1 1 2 3 4 300 aborted catalystmonobutyl- 7 9 12 15 17 19 180 Clear, tinoxide colorless 1a 7 10 18 90Clear, colorless 1b 3 6 7 9 11 14 90 Hazy, colorless 1c 4 4 10 14 16 75Clear, colorless 1d 3 6 10 12 14 16 90 Clear, colorless e 3 5 6 8 9 1013 15 18 135 Clear, colorless f 3 5 7 10 12 14 15 16 18 135 Clear,colorless

Example 3Catalytically Active Sn-compounds with A=Alcoholate Example 3oProduct of the reaction of monobutyl stannic acid with TI(OBu)₄ (molarratio,4:1) 10 51,1 9 (0,15 mol) TI(OBu)₄ and 25.3 9 (0,60 mol) monobutylstannic acid were dissolved In xylene (250 ml) and refluxed under anitrogen atmosphere In a 500 ml three necked round bottom flask for 4hours. The product was obtained after the solvent was removed underreduced pressure in an amount of 149,6 g (theoretical. 131,9 g) as ayellow 18 Example 3p Product of the reaction of monooctyl stannic acidwith Ti(OBU)₄ (molar ratio 1 : 1), synthesis in analogy to catalyst o.Example 3q Product from monooctylstannoic acid with tetrabutyl titanate(amount of substance ratio 4: 1), synthesis In analogy to Example 3o.Example 3r Product from monobutylstannoic acid with tetrabutyl titanate(molar ratio 2: 1), synthesis In analogy to Example 3o. Example 4Polycondensation of bis(2-hydroxyethyl) tereghthalate (BHET):Experimental method Polycondensation equipment 1 (glass equipment) forthe melt polycondensation of BHET Tempering-bath (salt bath),polycondensatlon vessel (glass), screw mixer (glass), vacuumpump,.pressure gauge As a polycondensation equipment a round glass flaskwith round bottom was used, (internal diameter 2,6 cm, and 35 cm height,described in T. Johnson, Chem. Fibers International 46 (1996) 280; 49(1999) 455). A horizontal vapor outlet Is integrated into the upperthird of the flask wall. A further extension tube near the bottom of thevessel allowed sampling from the polymer melt. The stirrer was aglassware screw mixer, reaching down to the ground (1,8 cm diameters).The mixer was 19-operated with a rotation speed of 100 min-3 andIntermixed the melt with axially downward direction. 25,4 g (0,1 mol)BHET were filled into the polycondensation vessel, the catalyst (5 to200 ppm as metal) was added and the vessel locked. Then thepolycondensation vessel filled with the reaction mixture was evacuatedthree times and flushed with dry nitrogen before It was immersed In thetempering-bath. The bath temperature was preset so that the desiredInternal temperature of 280° C. was reached in the polycondensationvessel. After the reaction mixture was melted, the stirrer was startedand the vessel evacuated within 15 min onto a vacuum of 2×10⁻¹ mbar. Thetime of the first formation of glycol at the wall of the glass wasregarded as to. The attainable final pressure for this equipment ofapproximately 4 to 5×10-2 mbar, was reached after approx. 1 hexperimental time, depending on the progress of the polycondensation.Through the sampling device samples could be taken by means of a VAsteel wire, maintaining a nitrogen counter flow. At the end of thereaction up to 5 g could be taken from the vessel for further analysis.During the polycondensation, an average sampling required one minute,from breaking the vacuum to re-applying the vacuum. At the end of thepolycondensation sampling was done within two minutes after aerating thevacuum.

PET characterization

The determination of the intrinsic viscosities was performed as follows:The relative solution viscosities r, for PET were determined in phenol(3 parts)/ dichlorobenzene (2 parts) mixtures using 0.5 percent20-solutions at 25° C. The conversion of the relative solutionviscosities into the intrinsic viscosity [(T] was done according toBILLMEIER.

Inrel -1 In nrel —X—————From the intrinsic viscosities (IV) the averagemolecular weights Mn (number average) as well as the degrees ofpolymerization Pn were calculated. For PET applies: Mn=(1000×IV)¹ ⁵¹⁸⁶;Pn=Mn/192 The absolute viscosities were measured using the viscosimeterAVS 250 and the tempering-unit CT 1450 of Schott Gercte GmbH, Germany.Comparison measurements between different laboratories gave matchingresults. The color values were determined using the CIE-LAB-Farbsystem(color system) by the spectral reference beam color measuring instrumentLUCI 100, Dr. Lange. The device STA 625 of Polymer Laboratories was usedfor TG and DSC-measurements. The COOH end groups were determined bypotentiometric titration of the in cresol solution of the polymers withdiluted aqueous NaOH. BHET and the catalyst were introduced Into thereaction vessel and rinsed well with nitrogen. 21-The reaction vesselwas placed into the salt bath. Recording of reaction time started now.Within 15 min the pressure was lowered from 100 mbar to 0,09 mbar. Atthe end of the reaction a pressure of 0,04 mbar was reached. Thefollowing table 2 shows the results of the polycondensation experimentsfor the catalysts of examples 1a, 3p and 3q in comparison to Sb- andTi-based catalysts (table 3). Criteria for determining catalyst activityare the attainable molecular masses in specific time periods, theIncreasing Influence of the thermal degradation, recognizable by theflattening of the Pn-t-function as well as the color values of thepolyester. The amount of the evolved ethanal (acetaldehyde) thatdirectly correlates with the degree of thermal ester group cleavage Is afurther essential criterion of the catalyst suitability. The colorvalues In the tables show the discoloration of the product, the a-valuesrepresenting green/red-gradients and the b-values representingblue/yellow-gradients. Negative a-values correspond to green, negativeb-values correspond to blue gradients. Blue shift is favoredtechnologically. The comparative Investigations for the catalyticactivity of the selected tin compounds show that no noteworthy thermaldecomposition is to be expected within 2 h of polycondensatlon time attemperatures of 280° C. Therefore It Is absolutely possible tosynthesize even higher molecular weight polyethylene terephthalates byprolongation of the polycondensation time. All examined tin compoundsproved to be high-activity catalysts for the polycondensation of BHETwhich showed significantly higher activity than stiblous compounds.Their polytransesterification activity was superior to that of titaniumalkoxides and titanium chelates. If required, they may alternatively beemployed In higher concentrations. TABLE 2 Polycondensation of BHET withthe catalysts of examples 1a, 3p and 3q. color values catalystconcentration using the of molar ratio Sn/Ti M_(n) CIE-LAB-systemexample [min] / Ti/Sn [ppm] [g/mol] P_(n) L a b 1a 30 0/1 116 2090 9 — —— 1a 60 0/1 116 3812 20 — — — 1a 90 0/1 116 6145 32 33.01 −0.05 1.18 1a120 0/1 116 16559 86 37.81 −0.46 2.64 3p 20 1:1 20/9   3839 20 3p 42 1:120/9   15454 80 67.15 −0.21 1.30 3p 96 1:1 20/9   25733 134 72.79 −1.030.61 3p 120 1:1 20/9   28454 148 68.06 −1.06 2.76 3q 15 1:4 20/2.25 16358 3q 31 1:4 20/2.25 4734 24 86.69 −0.87 −4.38 3q 60 1:4 20/2.25 13499 7070.38 −0.38 −0.31 3q 90 1:4 20/2.25 18759 97 73.54 −0.60 1.43

TABLE 3 Polycondensation of BHET with Sb and Ti catalysts. temperaturetime catalyst conc. catalyst [° C.] [min] [ppm] P_(n) antimonytriacetate 270 30 190 25 antimony triacetate 270 60 190 45 antimonytriacetate 270 90 190 65 antimony triacetate 270 120 190 85 antimonytriacetate 270 150 190 100 antimony triacetate 270 180 190 115 antimonytriacetate 280 30 190 30 antimony triacetate 280 60 190 55 antimonytriacetate 280 90 190 75 antimony triacetate 280 120 190 95 antimonytriacetate 280 150 190 115 antimony triacetate 280 180 190 135tetrabutyl titanate 280 30 20 45 tetrabutyl titanate 280 60 20 65tetrabutyl titanate 280 90 20 85 tetrabutyl titanate 280 120 20 105tetrabutyl titanate 280 150 20 125 tetrabutyl titanate 280 180 20 150

Further polycondensation reactions starting from bis-(2-hydroxyethyl)-terephthalate (BHET) were carried out In the glass equipment with screwmixer In presence of the catalysts 1 until 12.

Catalyst of comparative example 1g : tributyltin (2-ethylhexanoate) o -Catalyst of comparative example 1h: dibutyltin bis(2-ethylhexanoate) -Catalyst of example If: monobutyltin tris (2-ethylhexanoate) - Catalystof comparative example 11: dlbutyitin pinacolate - Catalyst of example1k: monooctylstannoic acid - Catalyst of example 11: monobutylstannoicacid - Catalyst of example 1m: monooctyltin tris(2-ethylhexanoate) -Catalyst of example 1n: monododecyltin tris(2-ethylhexanoate) - Catalystof example 3o: conversion product from monobutylstannoic acid withtetrabutyl titanate (4 Mol : 1 Mol) - Catalyst of example 3p: conversionproduct from monooctylstannoic acid with tetrabutyl titanate (1 Mol: 1Mol) - Catalyst of example 3q: conversion product from monooctylstannoicacid with tetrabutyl titanate (4 Mol : 1 Mol) - Catalyst of example 3r:conversion product from monobutylstannoic acid with tetrabutyl titanate(2 Mol : 1 Mol) For the determination of the catalyst activity at firsttwo concentrations of 20 ppm and 100 ppm were compared. The catalysts of(comparative) examples 1g through lj were dissolved in toluene. Thecatalysts were dissolved in dry toluene. The neat tin catalysts wereused at a catalyst concentration of 40 ppm. The mixed catalysts(catalyst of examples 3o through 3q) were used at a tin content of 20ppm. For the catalyst of example 3r the tin content of the catalyst was22.9 ppm. The tables 4a and 4b show the tin content and dosed catalystamounts of the respective experiments. BHET and the catalyst wereintroduced into the reaction vessel and rinsed well with nitrogen. Thereaction vessel was placed Into the salt bath. Recording of reactiontime started now. Within 15 min the pressure was lowered from 10025-mbar to 0,09 mbar. At the end of the reaction a pressure of 0,04 mbarwas reached. The results are shown in the tables 5 to 15. The followingtables show the results of the polycondensation experiments. Criteria ofthe catalyst activity are the attainable molecular masses In specifictime periods, the increasing Influence of the thermal degradation,recognizable by the flattening of the Pn-t-function as well as the colorvalues of the polyester. The amount of the evolved ethanal that directlycorrelates with the degree of thermal ester group cleavage is a furtheressential criterion of the catalyst suitability. The color values in thetables show the discoloration of the product, the a-values representinggreen/red-gradients and the b-values representing blue/yellow-gradients.Negative a-values correspond to green, negative b-values correspond toblue gradients. Blue shift is favored technologically. The comparativeInvestigations for the catalytic activity of the selected tin compoundsshow that no noteworthy thermal decomposition is to be expected within 2h of polycondensation. time at temperatures of 280° C. Therefore It isabsolutely possibly to synthesize even higher molecular weightpolyethylene terephthalates by prolongation of the polycondensationtime. All examined tin compounds proved as high-activity catalysts forthe polycondensation of BHET which show significantly higher activitythan stiblous compounds. Their polytransesterificatlon activity issuperior to titanium alkoxides and titanium chelates. If required, theycan be employed also In higher concentrations. For thebutyltin(2-ethylhexanoates) the activity sinks with Increasing alkylsubstitution. With regard to the achieved color values the monoalkyltintricarboxylate are preferred to the di- and trialkyltin carboxylates.TABLE 4a Tin content and added catalyst amounts catalyst in catalyst ofamount in reaction example/ tin 50 ml stock catalyst in reaction mixturefor comparative content solution mixture for 20 100 ppm Sn example [%][mg] [mg] [mg] 1g 27.8 182.27 1.8227 9.137 1h 22.9 221.8 2.218 11.09 1i20.0 254.0 2.54 12.7 1j 35.1 144.7 1.447 7.24 1k 44.0 5.780 1l 56.04.535

TABLE 4b Tin content and added catalyst amounts catalyst of example/ tinamount of catalyst in 50 amount of catalyst in the comp. content mlstock solution reaction mixture example [%] [mg] [mg]/[ppm] Sn 1m 17.5580.57 5.8/40 1n 16.1 631.06 6.3/40 3o 21.0 241.9 2.4/20 3p 37.0 137.31.4/20 3q 37.5 155.5   1.6/22.9 3r 46.5 109.24 1.1/20

TABLE 5 Polycondensation of BHET in presence of the catalyst ofcomparative example 1g color values using the time concentration M_(n)CIE-LAB-system [min] Sn [ppm] [g/Mol] P_(i) L a a 15 100 3127 16 40.80−0.34 −2.06 30 100 5953 31 36.15 −0.22 0.04 60 100 13943 72 29.68 −0.030.18 90 100 20281 105 30.04 0.04 0.52 120 100 23083 120 50.56 −1.65 1.3630 20 3046 16 60 20 5972 31 40.3 −0.64 −3.51 90 20 9933 51 32.33 −0.39−1.47 120 20 13356 69 47.88 −0.49 −0.20

TABLE 6 Polycondensation of BHET in presence of the catalyst ofcomparative example 1h color values using the time concentration M_(n)CIE-LAB-system [min] Sn [ppm] g/Mol] P_(n) L a a 16 100 3563 18 111−2.89 −12.29 30 100 8099 42 71.9 −0.57 −1.11 60 100 18585 96 73.3 −0.480.17 90 100 22289 116 70.9 −0.61 1.46 120 100 27090 141 74.4 −0.71 1.9430 20 5563 29 78.3 −1.15 −5.68 60 20 9172 47 70.3 −0.34 −1.13 90 2013294 69 66.4 −0.30 1.07 120 20 17636 92 72.1 −0.3 0.0

TABLE 7 Polycondensation of BHET in presence of the catalyst of example1l color values using the time concentration M_(n) CIE-LAB-system [min]Sn [ppm] [g/Mol] P_(n) L a a 15 100 4911 25 30 100 10779 56 82.4 −1.850.83 60 100 19581 102 71.7 −1.14 3.94 90 100 25191 131 65.9 −1.32 8.52120 100 28701 149 69.5 −1.11 7.69 30 20 6218 32 60 20 11572 60 75.7−0.42 −1.01 90 20 14656 76 68.8 −0.16 0.57 120 20 19130 99 83.58 −1.00−0.29

TABLE 8 Polycondensation of BHET in presence of the catalyst ofcomparative example 1j color values using the time concentration M_(n)CIE-LAB-system [min] Sn [ppm] [g/Mol] P_(n) L a a 15 100 1995 10 30 1003238 17 60 100 14769 77 81.4 −2.89 −0.96 90 100 20684 107 71 −1.21 4.13120 100 24106 125 73.8 −1.52 5.4

TABLE 9 Polycondensation of BHET in presence of the catalyst of example1k color values using the time concentration M_(n) CIE-LAB-system [min]Sn [ppm] [g/Mol] P_(n) L a b 15 100 3066 16 30 100 9071 47 70.9 −0.490.68 60 100 18234 95 69.3 −1.12 4.47 90 100 25817 134 82.5 −1.65 13.4120 100 27261 142 79.2 −1.09 10.1

TABLE 10 Polycondensation of BHET in presence of the catalyst of example1l color values using the time concentration M_(n) CIE-LAB-system [min]Sn [ppm] [g/Mol] P_(n) L a a 15 100 1932 10 30 100 7241 37 111.2 −4.7−4.84 60 100 16217 84 74.7 −2 5.07 90 100 21936 114 70.3 −1.2 6.28 120100 24761 129 69.9 −1.45 9.92

TABLE 11 Polycondensation of BHET in presence of the catalyst of example1m color values using the time concentration M_(n) CIE-LAB-ssystem [min]Sn [ppm] [g/Mol] P_(n) L a b 15 40 2437 12 31 40 5494 28 81.07 −1.86−7.12 45 40 8602 44 71.80 −0.31 −0.23 60 40 11282 58 71.52 −0.40 0.40 9040 16914 88 68.03 −0.21 2.70 120 40 20107 104 75.86 −0.83 2.51

TABLE 12 Polycondensation of BHET in presence of the catalyst of example1n color values using the time concentration M_(n) CIE-LAB-system [min]Sn [ppm] [g/Mol] P_(n) L a b 20 40 3317 17 40 40 7051 36 75.66 −0.57−2.49 60 40 11588 60 72.37 −0.50 −0.63 90 40 16132 84 64.23 −0.31 1.49120 40 20633 107 69.23 −0.66 1.68 160 40 24053 125 74.12 −0.97 2.59

TABLE 13 Polycondensation of BHET in presence of the catalyst of example3p and the catalyst of example 3q concen- color molar tration valuesusing the catalyst of time ratio Sn/Ti M_(n) CIE-LAB-system example[min] Ti/Sn [ppm] [g/mol] P_(n) L a b 3p 20 1:1 20/9   3839 20 3p 42 1:120/9   15454 80 67.15 −0.21 1.30 3p 96 1:1 20/9   25733 134 72/79 −1.030.61 3q 120 1:1 20/9   28454 148 68.06 −1.06 2.76 3q 15 1:4 20/2.25 16358 3q 31 1:4 20/2.25 4734 24 86.69 −0.87 −4.38 3q 60 1:4 20/2.25 13499 7070.38 −0.38 −0.31 3q 90 1:4 20/2.25 18759 97 73.54 −0.60 1.43 3q 120 1:420/2.25 23273 121 71.45 −0.77 1.09

TABLE 14 Polycondensation of BHET in presence of the catalyst of example3r and the catalyst of example 3o concen- Color catalyst molar trationvalues using the of time ratio Sn/Ti M_(n) CIE-LAB-system example [min]Ti/Sn [ppm] [g/mol] P_(n) L a b 3r 20 1:2 20/4.5  1259 6 3r 32 1:220/4.5  5043 26 111.81 −2.42 −4.93 3r 60 1:2 20/4.5  15788 82 78.13−0.93 0.00 3r 90 1:2 20/4.5  19198 100 69.56 −0.83 1.88 3r 120 1:220/4.5  23098 120 87.40 −2.06 4.53 3r 20 1:4 20/2.25 1687 8 3r 40 1:420/2.25 8181 42 71.67 −0.16 −0.64 3o 60 1:4 20/2.25 14469 75 77.63 −0.31−0.56 3o 90 1:4 20/2.25 17388 90 82.78 −0.63 1.21 3o 120 1:4 20/2.2524460 127 78.06 −0.74 0.77

s Catalytic activity depending on the structure of the tin compoundsTABLE 15 Effective rate constants of the polycondensation of BHET inpresence of tin compounds and/or tin-titanium mixed compounds Catalystof k * 10³ k * 10³³ k * 10³ example/ [mmol/g sec] [mmol/g sec] [mmol/gsec] [comparative Sn 20 ppm resp. Sn 40 ppm resp. Sn 100 ppm resp.example] 4 * 10⁻⁵ mol/mol 8 * 10⁻⁵ mol/mol 2 * 10⁻⁴ mol/mol 3p 4.8 3r4.0 3q 3.5 3o 3.5 1I 2.8 3.1 5.3 1k 3.4 4.4 1m 3.1 1n 3.0 [1h] 2.5 4.4[1j] 4.2 1l 3.9 [1g] 1.7 3.6

s Ex-amp~le 5: poQlycondensation- startina with terephthaiic acid an3dethylne alycol Experimental method 10 Polycondensatlon equipment 2 (15liab reactor of the Co. Juchheim, Germany) for the direct esterificationand polycondensation of direct esterification products. The equipmentconsisted of a stainless steel double jacket mixing tank 15s reactorwith 15 liters nominal volume and with conical bottom equipped withbottom discharge. The mixer was a double lever mixer, which fitted tothe conical bottom, with speed control and torque measurement. A glidering seal with ethylene glycol formed the mixer lock as a sealing-liquid. The preheating of the mixing tank reactor was performed througha liquid circulation heating. The control of the temperature of the heatcarrier was performed through a high temperature controller depending onthe preset temperature In the reactor Interior. At the lid of thereactor a feed hopper, gas dispersion tube, pressure gauge, thermometer(dipping tube), Inspection window, light, overflow valve, refluxcondenser and a Liebig condenser were Installed next to the mixer. Apipe condenser and a condensate receiver were downstream to the refluxcondenser, the Liebig condenser ended in a second condensate receiver.The condensate receiver had gassing/degassing valves, pressure gauge,overflow valve as well as a vacuum equipment at the lid next to thefeeding means. For the generation of the primary vacuum of approx. 20mbar a membrane pump was used and a rotary valve vacuum pump was used upto the final vacuum. The pressure control was done by means of vacuumcontroller in connection with a magnetic valve in front of thesucking-nozzle of the pump. The exits of the condensate receiver werecombined at the pressure point of measurement and connected through twocold traps switched In series and filled with liquid nitrogen. By meansof data printer following measuring data could be registeredcontinuously:

-   -   temperature at the lower Inside wall In the reactor -        temperature in the melt (dipping tube in the lid) - reflux        condenser head temperature - reactor internal pressure - torque        at the mixer shaft Esterificatlon, prepolycondensatlon and        polycondensation were carried out In one experimental step. 20        mol terephthalic acid (TPA) were premixed Intensely with 28 mol        ethylene glycol (EG) until homogeneous. To this mixture the tin        based s catalysts were added. This mixture was filled Into the        reactor having been flushed with nitrogen before. The reactor        was shut (time to), a mixer rotation speed set to 60 min and        heated up to 230 to 240° C. Internal temperature. The        temperature rise was followed by an Increase of pressure up to        approx. 4.5 bar. The generated water was distilled off 10 via        the reflux condenser, which was tempered at 115 *C. The head        temperature In this case was kept between 170 and 190° C.

The end of the esterification (time t₁) was indicated by a drop of thehead temperature and the Internal pressure. For the catalyst dosing theesterification product was cooled to approx. 180° C. for a short moment.

Then primary vacuum was applied and the reactor heated up to an internaltemperature of 270 to 275° C. Upon reaching the primary vacuum (approx.20 mbar) the rotary valve vacuum pump was started.

At a final pressure <0.1 mbar the polycondensation started (time t₂),recognizable by the Increasing torque. With high melt viscosities it wasnecessary to reduce the mixer rotation speed since the mixer shaft wasequipped with a shear-pen with a 60 Nm upper limit to protect the shaft.At the end of the polycondensation (time t₃) the mixer was disconnectedand the evacuated vessel was flushed with nitrogen. The product wasdischarged from the reactor by the bottom discharge under nitrogenpressure. It was either poured onto a steel sheet to cool down inpellets, or the melt was led through a water bath, granulated and theproduct dried subsequently.

The material was dried In a vacuum oven at 130° C. for 6 h, thenexamined with respect to the Intrinsic viscosities, and the color valueswere determined as described before.

The polycondensation starting out from terephthalic acid and ethyleneglycol were carried out In presence of the catalysts of examples 1l, 1n,and 3p.

Test conditions and results are shown in tables 16a and 16b. TABLE 16aTest conditions and polycondensation experiment in the 15l mixing tankreactor esteri- concen- fication polyconden- catalyst of T tration timesation time intrinsic example example [° C.] [ppm] [min] [min] viscosity5a 1l 275 53 Sn 180 105 0.85 5b 1l 275 26.5 Sn 180 180 0.87 5c 1l 270 53Sn 165 170 0.90 5d 1n 270 53 Sn 160 203 0.80 5e 3p 270 26.5 Sn 135 1100.92 +12 Ti

TABLE 16b Results of the polycondensation experiment in the 15l mixingtank reactor Content of end Content of Amount groups × COOH × ColorColor Color of M_(n) 10⁶ 10⁶ value value value ethanal example [g/Mol][mol/g] [mol/g] L a b [ppm] 5a 28200 79.9 24.5 59.02 −1.19 −3.21 24 5b29300 68.6 28 72.04 −2.08 0.28 15 5c 30700 65.1 25 70.53 −2.10 −1.20 285d 25600 82.3 23.5 58.14 −0.47 0.79 20 5e 31800 62.9 17 78.03 −2.62 1.1716

1-19. (canceled)
 20. A catalytic composition for esterification,transesterification. and polycondensation reactions of dicarboxylicacids, polycarboxylic acids and/or hydroxy carboxylic acids andalcohols, said catalytic composition containing a tin compound of thegeneral formula (I):[(R ¹ Sn)₁(OH)_(m-n)(OR ²)_(n) O _(o)]_(p+) A ^(q−) _(p/q)   (formula I)wherein: R1 and R² each independently is a linear, branched or cyclicalkyl group or aryl group having 1 to 12 carbon atoms, A^(q−) is ananion, l=12, m=6, n=0 to 6, o=14, p=2 and q=2.
 21. The catalyticcomposition according to claim 20, wherein the anion A^(q−) is O²⁻, OH⁻,a linear, branched or cyclic alkyl group, aryl carboxy group or alkoxygroup each having 1 to 12 carbon atoms, the anion of a mineral acid or ametalate.
 22. The catalytic composition according to claim 21, whereinthe anion A^(q−) is a sulphate, sulphite, phosphate, halogenide orpseudo-halogenide, titanate, zirconate, aluminate or zincate anion. 23.The catalytic composition according to claim 20, wherein the anionA^(q−) is a chloride anion and R¹ is an octyl- and/or butyl group.
 24. Aprocess for the preparation of a catalytic composition according toclaim 20, said process comprising the step of reacting a metal alkoxidewith a tin compound of the general formula:[(R ¹ Sn)_(l)(OH)_(m) O _(o)]^(P+) A ^(q−) _(p/q·)
 25. The processaccording to claim 24, wherein in the tin compound of general formula(I), n=1 to
 6. 26. The process according to claim 24, wherein said metalalkoxide and said tin compound are reacted in a mole proportion of1:0.0001 up to 1:20, in particular 1:4 to 1:6, respectively.
 27. Theprocess according to claim 26, wherein resultant metal oxides, metalhydroxides and/or alkoxy metal hydroxides remain in the catalyticcomposition.
 28. The process according to claim 24, wherein resultantmetal oxides, metal hydroxides and/or alkoxy metal hydroxides remain inthe catalytic composition.
 29. A method for the continuous or batchwiseproduction of esters or polycondensation products by esterification,transesterification, polyesterification or polytransesterificationreaction, said method comprising using the catalytic composition asdefined in claim
 20. 30. The method according to claim 29, comprising apolyesterification reaction of a dicarboxylic acid derivative with amono, divalent or polyvalent alcohol in the presence of the catalyticcomposition.
 31. The method according to claim 30, employing derivativesof di or polycarboxylic acids selected from the group of esters orhalogenides.
 32. The method according to claim 29, employing derivativesof di or polycarboxylic acids selected from the group of esters orhalogenides.
 33. The method according to claim 29, employing derivativesof hydroxycarboxylic acids selected from esters.
 34. The methodaccording to claim 29, employing a metal concentration of said catalyticcomposition in the range of 0.1 ppm to 1 mole percent, in particular10-100 ppm with reference to the acid or derivative to be reacted. 35.The method according to claim 29, employing a solvent or suspendingagent for the manufacturing of the catalytic composition and/or saidesterification, transesterification, polyesterification orpolytransesterification reaction.
 36. The method according to claim 35,employing the same solvent and/or suspending agent in the manufacturingof said catalytic composition and said esterification,transesterification, polyesterification or polytransesterificationreaction.
 37. The method according to claim 35, employing a solvent orsuspending agent selected from the group consisting of mono-, di- orpolyvalent alcohols being reacted in said esterification,transesterification, polyesterification or polytransesterificationreaction.
 38. A composition comprising polyester for bottles, films,foils, yarn and/or molded padding, or resins for powder coatings ortechnical synthetic materials, obtained by a synthesis process employinga catalytic composition as defined in claim
 20. 39. The polyester orresin composition according to claim 38, wherein said polyester isselected from the group consisting of polyethylene terephthalate,poly-2,2-dimethylpropyl-1,3-terephthalate, polypropylene terephthalate,polydiethyleneglycol terephthalate, polybutylene terephthalate,polynaphthalene terephthalate, polyethylene naphthalate and mixturesthereof.